This invention relates to an improved method for aligning photographic enlarging equipment and a new tool useful therefor. More particularly, this invention relates to the construction and use of an improved leveling device for aligning the negative carrier to the baseboard of a photographic enlarger.
Typical photographic enlargers consist of a projection light source, a negative carrier, a focussing mechanism and a baseboard. In use, the negative to be enlarged is placed in the negative carrier and light is projected through the negative and the focussing mechanism onto photographic paper located on the baseboard.
Typical enlargers permit adjustment of the plane of the negative carrier to enhance the resultant photographic image; for example, to alter the perspective of an image contained on the negative. However, precise reproduction of the negative image requires that the negative carrier be aligned in a plane parallel to that of the baseboard.
Previous enlarger alignment tools have utilized a simple linear spirit level mounted in adjustable spring-loaded cooperation with a flat base plate. The device was calibrated by placing it on the baseboard of the enlarger and an adjusting screw was used to align the bubble in the level element between two marks. The device was next moved to the negative carrier to be aligned in the same linear orientation in which it has been calibrated. The negative carrier was then adjusted until the bubble in the spirit level element was again aligned between the two marks, indicating that the planes were aligned in one axis. The process was then repeated for the axis perpendicular to that in which the planes had just been aligned.
One disadvantage of the prior alignment tool was that it required several successive alignment steps. Adjusting the planes in the second axis often disrupted the results of the first alignment, creating difficulties and delay in precise alignment of the negative carrier and the baseboard.
The tool of the present invention eliminates this disadvantage by reducing the alignment process to a single simple operation.